Correlation Between Heavy Metals and Turtle Abundance in Ponds Near the Paducah Gaseous Diffusion Plant, Kentucky, USA

Abstract

Reptiles are declining globally, and environmental contamination has been suggested as a contributing factor; however, few studies have investigated the relationship between contamination and reptile populations. We performed a mark-recapture study at ponds near the Paducah Gaseous Diffusion Plant (PGDP), Kentucky, to determine if heavy metals had an impact on turtle populations. We measured concentrations of cadmium, chromium, copper, lead, and mercury in red-eared slider turtle (Trachemys scripta elegans) tissues and pond sediment and determined the correlation between metal concentrations and red-eared slider density. Metal concentrations measured in the current study were low, and turtle density was not significantly correlated with metal concentrations in tissues or sediment. However, we observed a trend of decreasing turtle density in ponds that had greater metal concentrations. Sex ratio and proportion of juveniles were significantly different among ponds, but it is unclear if these differences are related to contamination associated with the PGDP.

Select metal and metalloid surveillance of free-ranging Eastern box turtles from Illinois and Tennessee (Terrapene carolina carolina)

“…In recent years, reports of metals in reptiles have increased, but the impact on populations is unknown (Burger et al 1998;Hays and McBee 2010;Yu et al 2013), particularly in regard to terrestrial North America chelonians (Beresford et al 1981). Lead has been linked to wildlife population declines, including in reptiles (Grillitsch and Schiesari 2010).…”

“…They went on to hypothesize that turtles may provide an integrated approach to public health in that geographic area (Pellalo-Martinez et al 2011). Moreover, at an ecosystem level, decreased turtle abundance was associated with increased concentrations of certain heavy metals within a superfund site in the US (Yu et al 2013). Terrestrial chelonians, however, are less defined as biomonitors of contamination, in part because terrestrial systems are less homogenous than aquatic systems (Smith et al 2007).…”